Download dsport 2014 - Pulstar Spark Plugs

142_Cover_MJF_011 001 COVER_qx 4/9/14 2:56 PM Page 1
FIRST DRIVE: ’14 FORD FIESTA ST: CHEAP TURBO FUN
FUJI
TUNING
RECORD
HOLDER
THE CARS
786WHP T/A S2000
Taking Aim at New Records
9.2-SEC DAILY EVO
Streetable and Nearly Unbeatable
MASCULINE MIATA?
Would 374whp Convince You?
TWIN-CHARGED EVOX
Turbo+Supercharged Garage G-Force
THE TECH
SCION DRIFT TEAM
Gushi, Aasbo and Angelo Interviews
SPARK INTEREST
Science of Selecting the Right Plugs
THE SCENE
FORMULA D 2014
Favorites Upset, Big Crashes
D1GP DRIFT FUJI
Things Get Wet & Wild in Round 1
FREE IDRC
RULEBOOK
JUNE 2014 #142 dsportmag.com
JUNE 2014 (#142) TOP FUEL S2000 • 9.2SEC/DD EVO • 374WHP MIATA • TWIN-CHARGED EVO X • SCION DRIFT TEAM • SPARK TECH • FORMULA D 2014 & D1GP SEASON OPENERS
1:40.195
TOP FUEL S2000
GETTING PLUGGED
SCIENCE OF PERFORMANCE PLUGS
Text by Michael Ferrara // Photos by Jun Chen and Courtesy of Enerpulse and NGK
T
38 DSPORT_142
1. The Racing Plug
An iridium center electrode,
angled side electrode, recessed
insulator and cold heat range
allow this plug to ignite
mixtures and survive
environments where street
performance plugs would fail.
Plug gaps are as small as
0.016” and typically at or
under 0.024” on forcedinduction applications.
2. Street Performance Plug
STREET
An iridium, platinum, silver or
nickel alloy center electrode is
typical for high-performance
street plugs. Projected nose
insulators and colder than
stock (but higher than racing)
heat ranges are typical.
RACING
ODAY’S PERFORMANCE SPARK PLUGS PERFORM FEATS
never before attempted by spark plugs of year’s past. Factory
engines and race engines are pushing more horsepower per
liter than ever before thanks in part to forced induction and direct
injection. Both of these technologies put an additional stress
on the engine’s ignition system. With the spark
plugs representing the soldiers in the field, we
decided to take a look at the technologies in
use. Today, platinum and iridium have
replaced nickel-alloys in many performance
and long-service applications. So are a set of
Iridium plugs right for you? What about the
latest generation of spark plugs featuring
plasma technology? The answer depends on
your particular performance combination.
Engines with marginal ignition systems or
those with high-voltage demands will see
the biggest performance gains from this
family of super plugs.
1
2
142_DSPORT
39
GETTING PLUGGED
SCIENCE OF PERFORMANCE PLUGS
Text by Michael Ferrara // Photos by Jun Chen and Courtesy of Enerpulse and NGK
T
38 DSPORT_142
1. The Racing Plug
An iridium center electrode,
angled side electrode, recessed
insulator and cold heat range
allow this plug to ignite
mixtures and survive
environments where street
performance plugs would fail.
Plug gaps are as small as
0.016” and typically at or
under 0.024” on forcedinduction applications.
2. Street Performance Plug
STREET
An iridium, platinum, silver or
nickel alloy center electrode is
typical for high-performance
street plugs. Projected nose
insulators and colder than
stock (but higher than racing)
heat ranges are typical.
RACING
ODAY’S PERFORMANCE SPARK PLUGS PERFORM FEATS
never before attempted by spark plugs of year’s past. Factory
engines and race engines are pushing more horsepower per
liter than ever before thanks in part to forced induction and direct
injection. Both of these technologies put an additional stress
on the engine’s ignition system. With the spark
plugs representing the soldiers in the field, we
decided to take a look at the technologies in
use. Today, platinum and iridium have
replaced nickel-alloys in many performance
and long-service applications. So are a set of
Iridium plugs right for you? What about the
latest generation of spark plugs featuring
plasma technology? The answer depends on
your particular performance combination.
Engines with marginal ignition systems or
those with high-voltage demands will see
the biggest performance gains from this
family of super plugs.
1
2
142_DSPORT
39
G ETTIN G PLU G G ED :SCIEN CE O F PERFO RM A N CE PLU G S
FUNCTION
OF THE SPARK PLUG
1. Converts high-voltage energy from
ignition coil to a spark.
2. Its spark initiates combustion.
3. Heat range of plug establishes the
regulated temperatures of the plug.
4. Provides a window to the soul of the
engine (in cylinder datalogger).
Function of the Spark Plug
The primary function of the spark plug is to create a spark that initiates
the combustion process within the cylinder. While this job sounds
simple enough, the environment where a spark plug lives is far from
friendly. A spark plug is subjected to electrical voltages that may
approach 40,000 volts. In addition to the electrical shock, cylinder
pressures may exceed 1,500 psi during combustion. At the same time,
in-cylinder temperatures can soar above 2,000 degrees Celsius then
instantly drop to outside temperatures when cool fresh intake air is
drawn into the cylinder. If you have ever poured hot water in a chilled
glass or ice cold water in a hot glass, then you’ve seen first hand the
damage that can be done by thermal shock or loading. Yet through all
this, a quality spark plug can survive and thrive.
A Better Plug
If you are looking for maximum performance, there are certain spark plugs
that are designed to minimize misfires or maximize the combustion of the airfuel mixture. If you are looking for maximum service intervals, there are spark
plugs that are designed for limited gap erosion, allowing them to function
two to five times longer than conventional plugs. If you are on a limited
budget, there may be plugs available that provide a heat range that’s
optimized for your engine’s modifications and your driving style.
HEAT RANGES
colder plug (Champion, AC Delco,
Bosch). Always check the
manufacturer’s catalog or web
site to make sure that you are
ordering the correct heat range.
Spark Voltage
How does a spark occur? All spark
plugs have air gaps. The gap is the
space between the plug’s center
and side electrode. When the
ignition system is triggered, high
voltage electrical energy is sent
down through the plug’s center
electrode. If the voltage of this
energy is high enough, a spark
occurs when the energy jumps
from the center to the side
electrode. So how much voltage is
Hot or Cold?
One of the most important considerations when choosing a replacement
spark plug is being sure that the correct heat range is chosen. If the
replacement plug that is chosen is too cold, fouling occurs. This leads to
misfires, poor performance, increased emissions and reduced fuel economy.
If the replacement spark plug has a heat range that is too hot, the results are
even worse. The spark plug can become so hot that its temperature ignites
the fuel before the spark ever has a chance to fire, this is termed “preignition.” Pre-ignition can lead to severe engine damage or melted electrodes
at the very least. Most tuners end up using a plug that is one to two heat
ranges colder than the heat range of the original equipment spark plug.
However, ultra-high boost pressure or ultra-high compression ratios may
require spark plugs that are three to four heat ranges cooler. Since the side
effects of choosing a plug that’s too cold are much less problematic than the
results of choosing a plug that is too hot, it’s always safer to start with a
colder plug.
The length of the insulator will set the spark plug’s heat range. The
longer insulator nose will keep more heat in the spark plug, making a
“hotter” plug. This heat will help prevent carbon fouling at idle and
low-speed operation. However, a “colder” plug with a shorter insulator
may be needed when horsepower levels are increased or wide-openthrottle operation is the norm.
ELECTRODE ALLOY
To determine if your plug is of the correct heat range for your level of
modifications and driving style, you can inspect your plugs after a pass on the
dyno or a few miles of driving on the street. If the firing end of the plug is
covered in black soot and the insulator is also covered in soot, the plug that
you have chosen is too cold for your application. If the firing end of the plug
has a tan, light brown or light grey appearance on the insulator and
electrode, you’ve chosen a heat range that’s appropriate for your application.
If the electrodes appear melted, rounded or blistering is apparent on the
insulator, the heat range is too hot for your application.
The amount of voltage required
to make a spark in the cylinder
is directly proportional to
cylinder pressure. More pressure
equals more voltage
requirements. Hence the voltage
requirements on boosted
engines are much higher than
naturally-aspirated engines.
needed for a spark to be
produced? The answer is that it
varies. Under certain conditions
10,000 volts may be enough
voltage, where under other
conditions 40,000 to 50,000 volts
may
be
required.
Higher
compression ratios and high boost
levels significantly raise voltage
requirements.
You may have seen some spark plugs advertise a “copper-core” construction.
Spark plugs that utilize a copper-core construction will generally be superior
in heat and fouling resistance when compared to plugs that do not have a
copper-core. A word of warning about heat range nomenclature: some spark
plug manufacturers use higher numbers to indicate a colder plug (NGK,
Denso, HKS, A’PEXi, GReddy), while others use lower numbers to indicate a
ALLOY COMPARISONS
Melting Point (F)
Ir
Pt
Ni
Au
Ag
4449
3216
2647
1945
1760
Strength (Kpsi)
159
20
97
19
19
Electrical Resistance
2.09
4.17
2.69
0.9
0.63
Hardness
240
40
160
25
26
40
DSPORT_142
Nickel-alloy is the most common material used for spark plug
electrodes. It has high strength and hardness providing for a long
service life. Platinum was one of the first premium alloys offered in
spark plugs. While not as hard, strong or conductive as nickel, it offers
an exceptional resistance to high-temperature oxidation and erosion.
Hence, it can be used in applications where 100,000 miles is desired
between plug changes. Iridium provides the best of both worlds. Since
it is harder, stronger and more conductive than nickel or platinum, it
offers exceptional performance along with a long service life.
Air-fuel ratios also influence the
voltage requirements. Gasoline
A/F ratios between 10.5:1 and
12.5:1 require the least voltage
and are the easiest to ignite.
Mixtures richer or leaner than
this require higher voltages.
142_DSPORT
41
G ETTIN G PLU G G ED :SCIEN CE O F PERFO RM A N CE PLU G S
FUNCTION
OF THE SPARK PLUG
1. Converts high-voltage energy from
ignition coil to a spark.
2. Its spark initiates combustion.
3. Heat range of plug establishes the
regulated temperatures of the plug.
4. Provides a window to the soul of the
engine (in cylinder datalogger).
Function of the Spark Plug
The primary function of the spark plug is to create a spark that initiates
the combustion process within the cylinder. While this job sounds
simple enough, the environment where a spark plug lives is far from
friendly. A spark plug is subjected to electrical voltages that may
approach 40,000 volts. In addition to the electrical shock, cylinder
pressures may exceed 1,500 psi during combustion. At the same time,
in-cylinder temperatures can soar above 2,000 degrees Celsius then
instantly drop to outside temperatures when cool fresh intake air is
drawn into the cylinder. If you have ever poured hot water in a chilled
glass or ice cold water in a hot glass, then you’ve seen first hand the
damage that can be done by thermal shock or loading. Yet through all
this, a quality spark plug can survive and thrive.
A Better Plug
If you are looking for maximum performance, there are certain spark plugs
that are designed to minimize misfires or maximize the combustion of the airfuel mixture. If you are looking for maximum service intervals, there are spark
plugs that are designed for limited gap erosion, allowing them to function
two to five times longer than conventional plugs. If you are on a limited
budget, there may be plugs available that provide a heat range that’s
optimized for your engine’s modifications and your driving style.
HEAT RANGES
colder plug (Champion, AC Delco,
Bosch). Always check the
manufacturer’s catalog or web
site to make sure that you are
ordering the correct heat range.
Spark Voltage
How does a spark occur? All spark
plugs have air gaps. The gap is the
space between the plug’s center
and side electrode. When the
ignition system is triggered, high
voltage electrical energy is sent
down through the plug’s center
electrode. If the voltage of this
energy is high enough, a spark
occurs when the energy jumps
from the center to the side
electrode. So how much voltage is
Hot or Cold?
One of the most important considerations when choosing a replacement
spark plug is being sure that the correct heat range is chosen. If the
replacement plug that is chosen is too cold, fouling occurs. This leads to
misfires, poor performance, increased emissions and reduced fuel economy.
If the replacement spark plug has a heat range that is too hot, the results are
even worse. The spark plug can become so hot that its temperature ignites
the fuel before the spark ever has a chance to fire, this is termed “preignition.” Pre-ignition can lead to severe engine damage or melted electrodes
at the very least. Most tuners end up using a plug that is one to two heat
ranges colder than the heat range of the original equipment spark plug.
However, ultra-high boost pressure or ultra-high compression ratios may
require spark plugs that are three to four heat ranges cooler. Since the side
effects of choosing a plug that’s too cold are much less problematic than the
results of choosing a plug that is too hot, it’s always safer to start with a
colder plug.
The length of the insulator will set the spark plug’s heat range. The
longer insulator nose will keep more heat in the spark plug, making a
“hotter” plug. This heat will help prevent carbon fouling at idle and
low-speed operation. However, a “colder” plug with a shorter insulator
may be needed when horsepower levels are increased or wide-openthrottle operation is the norm.
ELECTRODE ALLOY
To determine if your plug is of the correct heat range for your level of
modifications and driving style, you can inspect your plugs after a pass on the
dyno or a few miles of driving on the street. If the firing end of the plug is
covered in black soot and the insulator is also covered in soot, the plug that
you have chosen is too cold for your application. If the firing end of the plug
has a tan, light brown or light grey appearance on the insulator and
electrode, you’ve chosen a heat range that’s appropriate for your application.
If the electrodes appear melted, rounded or blistering is apparent on the
insulator, the heat range is too hot for your application.
The amount of voltage required
to make a spark in the cylinder
is directly proportional to
cylinder pressure. More pressure
equals more voltage
requirements. Hence the voltage
requirements on boosted
engines are much higher than
naturally-aspirated engines.
needed for a spark to be
produced? The answer is that it
varies. Under certain conditions
10,000 volts may be enough
voltage, where under other
conditions 40,000 to 50,000 volts
may
be
required.
Higher
compression ratios and high boost
levels significantly raise voltage
requirements.
You may have seen some spark plugs advertise a “copper-core” construction.
Spark plugs that utilize a copper-core construction will generally be superior
in heat and fouling resistance when compared to plugs that do not have a
copper-core. A word of warning about heat range nomenclature: some spark
plug manufacturers use higher numbers to indicate a colder plug (NGK,
Denso, HKS, A’PEXi, GReddy), while others use lower numbers to indicate a
ALLOY COMPARISONS
Melting Point (F)
Ir
Pt
Ni
Au
Ag
4449
3216
2647
1945
1760
Strength (Kpsi)
159
20
97
19
19
Electrical Resistance
2.09
4.17
2.69
0.9
0.63
Hardness
240
40
160
25
26
40
DSPORT_142
Nickel-alloy is the most common material used for spark plug
electrodes. It has high strength and hardness providing for a long
service life. Platinum was one of the first premium alloys offered in
spark plugs. While not as hard, strong or conductive as nickel, it offers
an exceptional resistance to high-temperature oxidation and erosion.
Hence, it can be used in applications where 100,000 miles is desired
between plug changes. Iridium provides the best of both worlds. Since
it is harder, stronger and more conductive than nickel or platinum, it
offers exceptional performance along with a long service life.
Air-fuel ratios also influence the
voltage requirements. Gasoline
A/F ratios between 10.5:1 and
12.5:1 require the least voltage
and are the easiest to ignite.
Mixtures richer or leaner than
this require higher voltages.
142_DSPORT
41
G ETTIN G PLU G G ED :SCIEN CE O F PERFO RM A N CE PLU G S
Spark Plug Life
The elements on the spark plug that wear over time are the center and side
electrodes. The size and material of the electrodes determine the service life
of the spark plug. Conventional plugs use a nickel-alloy center electrode
typically measuring about 2.5mm in diameter. Most manufacturers
recommend changing conventional plugs every 25,000 to 35,000 miles, but
performance and economy gains are best when these conventional plugs are
changed every 10,000 to 15,000 miles. Platinum plugs use a platinum alloy
center electrode (which can also contain a small amount of Iridium). The
center electrode on most Platinum plugs is about 1.1mm in diameter. Most
SOME OF THESE PLUGS HAVE ULTRA-FINE
CENTER ELECTRODES THAT MEASURE
JUST 0.4MM IN DIAMETER.
manufacturers recommend 60,000 to 100,000 miles as an interval for
changing the plugs, but once again changing at 40,000 to 50,000 miles
should deliver a slight improvement in power and economy. During the last
ten years, Iridium plugs have hit the performance scene. Some of these plugs
have ultra-fine center electrodes that measure just 0.4mm in diameter.
Although a 0.4mm iridium center electrode is only 13% of the size (in area)
of a platinum electrode (less than 3% of the area of a conventional nickel
electrode), Iridium’s superior corrosion and wear resistance give an identical
service life to a 1.1mm platinum plug.
Get Ignited
VOLTAGE REQUIREMENTS
Increase
Increase Spark Plug Gap
X
Increase Cylinder Pressure
X
Leaner Air / Fuel Mixtures
X
High-Swirl Combustion Chamber
X
High EGR
X
Reduce Electrode Diameter
Decrease
X
All automotive engines that run on gasoline rely on a spark for ignition.
Without a good spark, it doesn’t matter how much air and fuel was stuffed
into the cylinder—no spark means misfire, and misfire means a loss of power.
A pressurized chamber simulates the pressure
inside the cylinder at the time of ignition. Higher
pressures increase voltage requirement on the
ignition system and deliver a more intense spark.
Some plugs, like the Pulstar plugs, use a plasma
technology to deliver an extremely intense and
short duration spark. Notive the difference
compared to the conventional plug under the
same conditions.
Today’s spark plugs are much different than the one’s found in the cars that
your parents drove when they were your age. Advances in material science
have provided better materials for the construction of spark plugs. Platinum
and Iridium have replaced nickel-alloys in many performance and long-service
applications. Are a set of Iridium plugs right for you? The answer depends on
your particular performance combination. Boosted or high-compression
applications will see the biggest performance gains from this family of super
plugs. Additionally, vehicles with direct-fire or marginal ignition systems will
also reap big benefits.
Remember, spark plug electrodes will erode over time and the plug gap will
increase. Don’t run a gap that’s on the edge of a misfire. When the sharp
edges wear off the new plugs and erosion begins, a significant amount of
misfires may result.
Smaller is Better?
Peak performance requires that misfires are minimized. The diameter of the
center electrode and the width of the spark plug gap influence the voltage
requirements for a spark to occur. With all other factors being equal, spark
plugs with smaller center electrodes will be able to generate a spark at a
lower voltage than spark plugs with a larger center electrode. Smaller spark
plug gaps also reduce the voltage requirements for a spark. When gaps go
too small, the spark kernel may be too small to initiate combustion.
Voltage requirements are a function of gap length, electrode diameter,
cylinder pressure and gas density. The bigger the spark plug gap, the higher
the minimum voltage to initiate a spark. As for electrode diameter, the
smaller the diameter the lower the voltage required for a spark to occur.
With cylinder pressure, the higher the pressures in the cylinder (the result of
high compression ratios and high boost levels), the more voltage required for
a spark to occur.
CONSIDER
WHEN SELECTING
1. Proper heat range for application.
2. Proper electrode gap.
3. Desired service interval for plug.
4. Benefits of premium alloy electrodes.
5. Need for reduced diameter center
electrodes (boosted applications).
6. Availability/practicality of using a spark
plug solution with “plasma” technology.
Pulstar uses a plasma technology to produce a very short duration,
high-intensity spark. In many street applications, this spark
profile provides increased performance, fuel economy and reduced
emissions. We’ve personally tested the plugs on a number of
applications with very favorable results. Pulstar offers plug
solutions for most applications/usages requiring a factory or onestep colder heat range.
42
DSPORT_142
READING THE SIGNS
While new technology provides consumers with tools to monitor
combustion chamber performance, technicians have been observing
or “reading” spark plugs for decades to get an idea of what’s going
on inside a motor. Seen here are spark plugs indicating a number of
problems within the cylinder.
Deposits – Spark plugs peppered with deposits indicates oil or some
other contaminant entering the combustion chamber. Instead of
fouling out the plug, the liquid material evaporates and leaves
behind crystal-like particles capable of deteriorating the plug and
engine internals quickly.
Dry Fouling – This is a common result in use of a colder heat range
spark plug in an engine that doesn’t operate frequently at higher
temperatures. If this was a spark plug rated at the factory heat range,
other problems could be an overly-rich AFR, electrical problem
causing misfires or extended operation of little to no throttle load.
Speckling Plug – Seeing this condition is the first sign of too much
heat on the spark plug. Before assuming a step colder plug is the only
solution needed, make sure the engine itself isn’t overheating, the
AFR isn’t too learn and that the timing isn’t over-advanced.
Wet Fouling – While this is possible with an excessively cold plug or
rich AFR, a wet-fouled plug like this is more likely the result of oil or
some other contaminant being introduced into the combustion
chamber. The smell and appearance of the liquid on the plug would
be a key indication at what the problem is.
Melted Electrode/Cracked Insulator – This is what eventually happens
to plugs that face either extreme or extended conditions that cause a
plug to speckle. The excessive heat literally melts the metal and the
violent detonation breaks away the ceramic insulator. If a spark plug
is pulled out of an engine looking like this, expect to have more
engine parts needing replacement.
NORMAL
DRY CARBON FOULED
WET OIL FOULED
DEPOSITS + CRACKED INSULATOR
OVERHEATED METAL SPECKLING
MELTED ELECTRODE
142_DSPORT
43
G ETTIN G PLU G G ED :SCIEN CE O F PERFO RM A N CE PLU G S
Spark Plug Life
The elements on the spark plug that wear over time are the center and side
electrodes. The size and material of the electrodes determine the service life
of the spark plug. Conventional plugs use a nickel-alloy center electrode
typically measuring about 2.5mm in diameter. Most manufacturers
recommend changing conventional plugs every 25,000 to 35,000 miles, but
performance and economy gains are best when these conventional plugs are
changed every 10,000 to 15,000 miles. Platinum plugs use a platinum alloy
center electrode (which can also contain a small amount of Iridium). The
center electrode on most Platinum plugs is about 1.1mm in diameter. Most
SOME OF THESE PLUGS HAVE ULTRA-FINE
CENTER ELECTRODES THAT MEASURE
JUST 0.4MM IN DIAMETER.
manufacturers recommend 60,000 to 100,000 miles as an interval for
changing the plugs, but once again changing at 40,000 to 50,000 miles
should deliver a slight improvement in power and economy. During the last
ten years, Iridium plugs have hit the performance scene. Some of these plugs
have ultra-fine center electrodes that measure just 0.4mm in diameter.
Although a 0.4mm iridium center electrode is only 13% of the size (in area)
of a platinum electrode (less than 3% of the area of a conventional nickel
electrode), Iridium’s superior corrosion and wear resistance give an identical
service life to a 1.1mm platinum plug.
Get Ignited
VOLTAGE REQUIREMENTS
Increase
Increase Spark Plug Gap
X
Increase Cylinder Pressure
X
Leaner Air / Fuel Mixtures
X
High-Swirl Combustion Chamber
X
High EGR
X
Reduce Electrode Diameter
Decrease
X
All automotive engines that run on gasoline rely on a spark for ignition.
Without a good spark, it doesn’t matter how much air and fuel was stuffed
into the cylinder—no spark means misfire, and misfire means a loss of power.
A pressurized chamber simulates the pressure
inside the cylinder at the time of ignition. Higher
pressures increase voltage requirement on the
ignition system and deliver a more intense spark.
Some plugs, like the Pulstar plugs, use a plasma
technology to deliver an extremely intense and
short duration spark. Notive the difference
compared to the conventional plug under the
same conditions.
Today’s spark plugs are much different than the one’s found in the cars that
your parents drove when they were your age. Advances in material science
have provided better materials for the construction of spark plugs. Platinum
and Iridium have replaced nickel-alloys in many performance and long-service
applications. Are a set of Iridium plugs right for you? The answer depends on
your particular performance combination. Boosted or high-compression
applications will see the biggest performance gains from this family of super
plugs. Additionally, vehicles with direct-fire or marginal ignition systems will
also reap big benefits.
Remember, spark plug electrodes will erode over time and the plug gap will
increase. Don’t run a gap that’s on the edge of a misfire. When the sharp
edges wear off the new plugs and erosion begins, a significant amount of
misfires may result.
Smaller is Better?
Peak performance requires that misfires are minimized. The diameter of the
center electrode and the width of the spark plug gap influence the voltage
requirements for a spark to occur. With all other factors being equal, spark
plugs with smaller center electrodes will be able to generate a spark at a
lower voltage than spark plugs with a larger center electrode. Smaller spark
plug gaps also reduce the voltage requirements for a spark. When gaps go
too small, the spark kernel may be too small to initiate combustion.
Voltage requirements are a function of gap length, electrode diameter,
cylinder pressure and gas density. The bigger the spark plug gap, the higher
the minimum voltage to initiate a spark. As for electrode diameter, the
smaller the diameter the lower the voltage required for a spark to occur.
With cylinder pressure, the higher the pressures in the cylinder (the result of
high compression ratios and high boost levels), the more voltage required for
a spark to occur.
CONSIDER
WHEN SELECTING
1. Proper heat range for application.
2. Proper electrode gap.
3. Desired service interval for plug.
4. Benefits of premium alloy electrodes.
5. Need for reduced diameter center
electrodes (boosted applications).
6. Availability/practicality of using a spark
plug solution with “plasma” technology.
Pulstar uses a plasma technology to produce a very short duration,
high-intensity spark. In many street applications, this spark
profile provides increased performance, fuel economy and reduced
emissions. We’ve personally tested the plugs on a number of
applications with very favorable results. Pulstar offers plug
solutions for most applications/usages requiring a factory or onestep colder heat range.
42
DSPORT_142
READING THE SIGNS
While new technology provides consumers with tools to monitor
combustion chamber performance, technicians have been observing
or “reading” spark plugs for decades to get an idea of what’s going
on inside a motor. Seen here are spark plugs indicating a number of
problems within the cylinder.
Deposits – Spark plugs peppered with deposits indicates oil or some
other contaminant entering the combustion chamber. Instead of
fouling out the plug, the liquid material evaporates and leaves
behind crystal-like particles capable of deteriorating the plug and
engine internals quickly.
Dry Fouling – This is a common result in use of a colder heat range
spark plug in an engine that doesn’t operate frequently at higher
temperatures. If this was a spark plug rated at the factory heat range,
other problems could be an overly-rich AFR, electrical problem
causing misfires or extended operation of little to no throttle load.
Speckling Plug – Seeing this condition is the first sign of too much
heat on the spark plug. Before assuming a step colder plug is the only
solution needed, make sure the engine itself isn’t overheating, the
AFR isn’t too learn and that the timing isn’t over-advanced.
Wet Fouling – While this is possible with an excessively cold plug or
rich AFR, a wet-fouled plug like this is more likely the result of oil or
some other contaminant being introduced into the combustion
chamber. The smell and appearance of the liquid on the plug would
be a key indication at what the problem is.
Melted Electrode/Cracked Insulator – This is what eventually happens
to plugs that face either extreme or extended conditions that cause a
plug to speckle. The excessive heat literally melts the metal and the
violent detonation breaks away the ceramic insulator. If a spark plug
is pulled out of an engine looking like this, expect to have more
engine parts needing replacement.
NORMAL
DRY CARBON FOULED
WET OIL FOULED
DEPOSITS + CRACKED INSULATOR
OVERHEATED METAL SPECKLING
MELTED ELECTRODE
142_DSPORT
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